Biodegradable common bile duct stent and the method for preparing thereof

Abstract

A biodegradable common bile duct stent and the method for preparing thereof are provided. The stent is made of biodegradable polymeric material with incorporation of X-ray opaque components. The stent adapts to the anatomical shape of the CBD or it can be sutured together with the wall of the bile duct. After placing the stent in the duct, it maintains its position and does not slip. The circular tube of the stent being suitably sized and having multiple ring-shaped protruding rims at the outer wall and / or with larynx structure, leakage and outflow of the bile are thereby prevented. It can be manufactured by a conventional injection-molding or an extrusion-blowing technique. In surgical operation on the bile duct, the stent can replace the T-tube which is conventionally used to support the duct and guide bile drainage. It can reduce the time required for surgical operation and treatment, reduce possible complications and can be degraded and eliminated as the incision heals and the CBD regains its normal functions.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This Non-provisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No. 03148595.2 filed in CHINA on Jul. 7, 2003, the entire contents of which are hereby incorporated by reference.FIELD OF THE INVENTION[0002]The present invention relates to a biodegradable polymeric common bile duct (CBD) stent and its method of preparation.BACKGROUND OF THE TECHNOLOGY[0003]The common bile duct exploration (CBDE) is a common surgical operation for treating gall-stone, bile duct narrowing and related complaints. In CBDE, a longitudinal incision is made in the common bile duct (CBD) and sutured after the operation. Since simple suturing often includes bile leakage or bile duct narrowing, and thus causes further complications, in clinical practice a T-tube is usually inserted to provide a support during the operation and to keep the bile duct open afterwards. Bile or other secretions can either flow into the intestine through the...

AI Technical Summary

Benefits of technology

[0009](1) The stent provides a bolstering for the CBD wall so that it can be conveniently sutured in operation. After the operation it can prevent the occurrence of duct narrowing. The stent also has the function of expanding the bile duct for patients suffering from bile duct narrowing.

[0010](2) The stent can block the incision on the CBD wall and thus avoid the leakage of bile.

[0011](3) The stent can ensure free draining of bile into intestine completely without stasis or running off. Therefore it will not inflict harmful influence on liver functions and will eventually benefit motion of intestines and recovery of digestion functions.

[0012](4) Since the stent does not have drainage side tube, bile duct countercurrent infection and harmful effect on the surrounding tissues caused by the presence of T-tube can be avoided.

[0013](5) After the recovery of the bile duct functions, the stent undergoes biodegradation and the degraded products or fragments will flow into the intestine with the bile. It need not be taken out by a second surgical operation. This will alleviate the suffering of the patients, shorten the hospitalization time and lower the hospitalization expenses.

[0014](6) It can eliminate the inconvenience of body movement and the psychological dread of the patient due to the presence of T-tube in bile duct and can benefit the recovery of patients both physically and emotionally.

Problems solved by technology

The insertion of the T-tube may sometimes lead to complications: (1) it may cause an inflamatory reaction, leading to swelling and narrowing of the bile duct; (2) it can induce bile duct infection caused by the counterflow action through its long arm or the infection around the drainage exit at the abdominal wall; (3) if the outflow of bile from the long arm of the T-tube approaches 300–800 ml / day, water-electrolyte disorders and acid-base imbalances occur.

This may interfere with the normal mobility of intestine and inhibit the recovery of digestive functions; and (4) if the T-tube is left in position for an extended period it may cause pressure on the surrounding tissues and organs, possibly leading to perforation and adhesion.

Furthermore the sinus may not form properly or even break when the T-tube is removed and bile leakage may occur.

In such procedures it is very difficult to control the time and speed of transfer of the stent to the intestines and the procedure is thus difficult to be adopted clinically.

Because of the orientation of cutting and suturing, there is a high risk of bile leakage and bile duct narrowing.

Generally a T-tube is required with its associated risks of complications.

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